CVE-2026-64833: FFmpeg 0.7.1 - 8.1.2 Out-of-Bounds Read via S/PDIF Muxer spdifenc.c

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 29 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.4%

EPSS score, percentile 33.7 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

7.1 High

CVSS v4.0 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (1)

Which versions are affected?

Affected

• 0.7.1 through 8.1.2

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 29 Oct 2026. About the data.

What to do

Advisories and patches

• Patch Commit (Patch)

This summary is based on the CVE record as of 29 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Versions not listed are: affected.

Source: CVE List, as of 29 Oct 2026. About the data.

About this vulnerability

FFmpeg versions 0.7.1 through 8.1.2 contain an out-of-bounds read vulnerability in the S/PDIF muxer that allows attackers to access memory beyond buffer boundaries by supplying a crafted DTS stream with a core_size value larger than the actual packet length. Attackers can exploit the missing bounds check in the spdif_header_dts4 function by providing a malicious DTS-HD audio stream during S/PDIF…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-64833 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 22 Jul 2026.
• The CVE record carries a CVSS v4.0 base score of 7.1 (High), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.4% (percentile 33.7), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
• CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact partial.
• The credits in the CVE record name AISLE as finder.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; CVE List, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026. About the data.

Description

FFmpeg 0.7.1 - 8.1.2 Out-of-Bounds Read via S/PDIF Muxer spdifenc.c

FFmpeg versions 0.7.1 through 8.1.2 contain an out-of-bounds read vulnerability in the S/PDIF muxer that allows attackers to access memory beyond buffer boundaries by supplying a crafted DTS stream with a core_size value larger than the actual packet length. Attackers can exploit the missing bounds check in the spdif_header_dts4 function by providing a malicious DTS-HD audio stream during S/PDIF re-muxing to trigger unauthorized memory reads beyond the packet buffer.

Source: CVE List, as of 29 Oct 2026. About the data.

Timeline